Shank is a term used to describe two different parts of a lamb. The leg shank is a portion of the lamb's lower leg and contains a large amount of fat, while the lamb shank is a shoulder cut with less fat. However, both are trimmed in the same way. Both cuts of the meat usually are prepared slowly, cooked over low heat. The fat adds flavour to the dish, but trimming the lamb shanks removes the rubbery pieces of fat left behind after cooking.
Look for a piece of light grey- or silver-coloured tissue on the top of the lamb shank; this is called the fell. Slide the tip of your knife underneath the fell and gently work it around until you form a pocket. Use your hands to push the tissue down and away from the meat.
Turn the lamb shank on its wider end, holding the bone end side up and facing toward the ceiling. Adjust the meat so the fatty side is facing opposite you.
Insert the tip of the knife into the fatty pocket and slowly push down and away from you. Run the knife gently along the space between the meat and the fat. Remove any larger deposits of fat on the lamb shank.
Hold the top portion of the meat in one hand and use your other hand to slide the knife into the space between the meat and the centre bone. Slide the knife around the meat until you've gone a full rotation around the bone.
Push the knife down along the bone and gently pull the meat away from the bone. You want at least 5 cm (2 inches) of the bone open and exposed from the lamb shank. Tuck the flap of meat around the bottom of the shank. This is known as French trimming.
Leave a small amount of fat on the lamb shank to flavour the meat and keep it from drying out.
Always use caution when handling sharp knives.